hi Everyone!
Is it possible that partially clogged radiator will cause the tranny to run to hot even though the engine is not overheating? Engine runs cool all the time since i dont have the thermostat and its not overheating but my tranny started leaking fluid yeasterday when it got to hot...its not leaking in normal operating temps...So i figured it has to be the radiator problem not cooling the tranny fluid in the radiator tranny cooler (partially colgged radiator no circulation around the build in tranny cooler?)....is it possible or should i be looking at something else?....i have the factory tranny cooler in front of the radiator as well but for some reason tranny got to hot ..i wasnt towing anything but one of my calipers was locking up and there was more load on the tranny than usual just to get me home....
One more thing van was sitting for about a year....never had this problem before even when towing really heavy loads
91 3.0

Any healp really appreciated

thanks

dom

 

get brake calipers unstuck, will quickly overheat the high stall torque converter and ATF in the light duty A4LD tranny and burn out tranny clutches, bands and coat working parts with varnish....

after brakes fixed and vehicle freely rolls, change tranny fluid with gentle drain out front cooler return line with 10 qts of new Mercon /DextronIII ATF....search Aero forum
measure flow out at hot idle, should be minimum 1 qt every 20 seconds for working pump and open lines/coolers

what is now a quick simple cheap fix can quickly turn into a $2000 failed tranny

put back in 195d F thermostat or engine will be sludge bucket in 500 miles with no bearings

 

.....my '91 3.0 sat for a little over a year. Apparently during this time the front seal hardened up and at increased temp the fluid would dump out. I couldn't drive the van over 55 mph. I pulled the tranny had both the front and rear seal replaced, and the shop did something with the pump (replaced one or more O rings, I think.). Solved the problem, runs like new now...

 

listen to these guys, make sure the torque converter locks-up. Almost any cel code will prevent this, dopey engineers. An unlocked converter in cruise will cook the trans even with the largest trans cooler installed. Also an unlocked converter will greatly further enrich the oil companies. An a4ld in cruise with the converter locked will be cool as a cucumber and live forever.

Ken

ken

ken

 

A little clarification please. Is this statement true that you are running no thermostat?

 

Yes there is no thermostat it has been removed at some point or its stuck open ...havent checked yet but the temp gauge doesnt move all that much as it used to ..temp switch seems to be fine

 

I am still not sure how you tell weather the T.C. is locked up, is it when you reach 45mls and it changes up to 4th.? and when does the T.C unlock.? can anyone explane please.

 

Doman, replace the thermostat immediately! It is a $10 part that anyone can do in an hour.


Hopefully you have not toasted, your plugs, cats, cylinders, EGR, O2s, ect.

More than likely your Tranny is overheating because of the raw fuel (rich) that you are dumping into the cat causing it to overheat (which is right against the tranny. You are running rich because the computer is trying to get the engine to operating temp. It is not your radiator.

cbr900, usually you will feel a little jolt when it locks and unlocks. You will also feel the engine rpm slow down at highway speed when it kicks in. It is alot easier to see if you have a Tach.

 

Would having a 185 deg thermostat be a big deal?

The temperature now varies between O-R in NORMAL (after replacing the below items).

With a 195 thermostat installed I was running between R-M during normal driving (before replacing the below listed items). What made me change it was when I tow my 1200# tent trailer with gear the temp would run at M-A. That makes me nervous.

4.0 AWD ~185K
New Radiator, Fan Clutch, hoses, pump, and 185 thermostat (only the core left to go).

What is the temp range of the gauge? N=XXX and L=XXX?
Where does a healthy 4.0 with 195 thermostat run in the temp range?
Is oil sludge really caused by a low thermostat?

 

No Thermo or a low temp Thermo will cause sludge, it is not the only thing that will (like no oil changes) but it will. Also by running a lower temp Thermo, it is open more often which gives the fluid in the radiator less time to cool down.

I believe O would be around 195 sense that is where most of us 4.0L hang out at. It is a very inaccurate gauge so it is hard to tell what the temp is. The best way to check is with an infrared thermometor at the thermostat housing.

 

the ECU/PCM firmware is expecting only a 195d F theromostat...anything different and you will negatively affect engine performance, catalytic converter life, transmission shift points, fuel mileage, shorter engine and transmission life.
colder thermostat also reduces time tranny TC is shifted into lockup which reduces tranny killing heat....cold engine can overheat tranny

195d F thermostat only, FoMoCo OEM was 197d F....

if you want to mess with the moving Idiot Temp. Gauge stupid reading, pull a resistor in parallel with it to ground, start with abt 1k ohm or buy a high quality $200 aftermarket temp gauge.

if you have an overheating problem- fix it, put in larger new, clean US made 4L radiator, put in the largest plate type auto tranny cooler in front of the radiator that will fit in, turn off OD while towing or heavy loads and whenever driving in temps above 100d F

 

I would like to know how to get the 4.0L radiator to fit. I tried, but the upper hose was about .25 inch from the alternator pulley. Would have chewed through the hose in no time. There was no convenient place to put some kind of support to keep the hose away. My van is a '97 3.0. None of the radiator shops in the area carry a 2 row radiator for the 3.0. If anyone makes one, let me know.

There is an inhibit in the logic to prevent torque converter lockup and shifting into OD when the engine temperature is below about 130F or so. I can't remember the exact number, but it's in the Ford factory service manual.

The manuals for both my '95 and my '95 Aerostar only recommend turning off the OD when on hills to prevent the transmission from shifting excessively. It states that the tranny should be put back into OD when not on the hills for optimum drivetrain cooling. I think taking the tranny out of OD also unlocks the torque converter, but don't know for sure. When the torque converter is unlocked, a lot of heat is generated through torque converter slippage.

 

One thought for one and all is before adding a tranny cooler make sure the rubber lines going to and from are transmission lines not Fuel Injection or anything else. I've had some parts places tell me high pressure fuel lines are just fine. Beleive me they are not as I learned the hard way on my old Mercury Sable right before I blew a line out from excessive deteriation. I've never seen tranny fluid that's gone so close to black.

Dan

*edit - brain in wrong gear wrong word placement*

 

the torque converter will go into lockup in either 3rd or OD as long as rest of PCM requirements are met....Ford recommends towing and max. engine cooling in overheat conditions with OD locked out...reduces engine loading and increases water pump/fan blade rpm.....

try moving the radiator mounts forward 0.5 inches or so....i've seen 2 3L's that have the 4L radiators mounted, will look under the neighbor's hood the next time he has his hood up...he could not tow trailer on summer vacations before putting in 4L 2 row radiator, now no overheating problems even in desert and in the Rockys

 

Mikeman:

Try an Explorer radiator. I remember that the upper hose nipple on those things go straight out, not angled downward like the Aerostar 4.0L.